Diseases and Parasites of Horses

1. Diseases and Parasites of Horses Animal Science I Unit 33

2. Objectives • Identify common diseases and parasites of horses • Describe prevention measures for diseases and parasites of horses

3. Proper Feeding and Management • Dusty or moldy feed should never be used • The mycotoxin fumonisin is sometimes found in moldy corn. It is toxic to animals and may cause brain and liver disorders in horses. • Water consumption after hard work should be carefully controlled

4. Cleanliness and Sanitation • Prevent the growth of disease organisms and parasites • Helps break the life cycle of many parasites • Do not keep horses in barns that are warm and humid

5. Immunization and Parasite Control • Vaccinate • De-worm

6. Preventing Spread of Disease • Isolate sick animals • Keep water and feed containers separate as well • Call a vet

7. Vital Signs • Temp: 99-100.8 • Average is 100.5 • Temp. is usually higher in the morning than the afternoon and younger animals will show a wider range of temps. • Pulse Rate- 32-44 BPM • Respiration- 8-16 breaths per minute

8. Diseases and Disorders

9. Anhydrosis • Condition in which horses do not sweat normally • Management practices • Riding and working the horse only when cool • Keeping the horse out of sun • Using fans and air conditioning • Feeding a higher fat diet • One treatment that has shown success is using a thyroid medication

10. Anthrax • Symptoms • High fever, blood in the feces, rapid breathing, swelling on the body, especially the neck, depression in later stages • May bleed from all body openings • Death rate is high • Controls • Isolate sick horses • Vaccinate healthy ones • Quarantine the area, change pastures, practice strict sanitation • Prevented by Vaccination

11. Anthrax

12. Azoturia (Monday-Morning Sickness) • Develops when a horse is put to work following a period of idleness • Symptoms • Stiffness, sweats, dark colored urine • Muscles become swollen, tense and paralyzed • Prevention • decrease the amount of grain fed while the horse is idle • Exercise when idle • Start back to work slowly • If symptoms appear • Stop work and movement • Use blankets to keep the horse warm and dry • Call the vet.

13. Bruises and Swelling • Apply cold compresses until the bleeding and swelling stop • Apply heat and liniments to the affected area

14. Colic • Encompasses a wide range of conditions that affect the digestive tract • Usually caused by some type of abdominal obstruction that blocks the intestine, resulting in pain • Pain is caused when the intestine is distended by an accumulation of gas, fluid or feed • Must be treated immediately

15. Colic • Causes • Parasites, (large strongyles (blood worms) • Nutritional factors • Teeth or mouth problems • drinking excessive quantities of cold water before being cooled out after heavy exercise • Diseases that cause high fever and reduce intake of feed and water • Feeding excessive amounts of grain • Twisting the intestine

16. Colic • Symptoms • Sever abdominal pain • Uneasiness or restlessness • Looking at the flank region • Getting up and down • Kicking at the belly • Sweating • Shifting weight • As the problem continues the horse may lie down and roll, have an increased pulse and respiration rate, congested gums, strain, sweat, and bloat

17. Colic • Prevented by good management practices • If colic develops call the vet, as it can be treated satisfactorily if treating is started quickly

18. Colic Surgery

19. Distemper (Strangles) • Caused by a bacterium • Spread quickly by contaminated feed, water troughs, tack or direct contact • Young horses are more likely to get it than old • Symptoms • High fever, loss of appetite, depression, puslike discharge from the nose, lymph nodes in the lower jaw and throat swell • Treat with antibiotics and isolate newly arrived animals for 2-4 weeks • Vaccinate if the farm has a history of distemper.

20. Distemper (Strangles)

21. Encephalomyelitis (Sleeping Sickness) • Affects the brain • Common forms are known as Eastern and Western • Carried by mosquitoes • Symptoms • High fever, depression, lack of coordination, lack of appetite, drowsiness, drooping ears, circling • May die or recover • Death rate is as high as 90% from the Eastern and Venezuelan types • 20-30% for the Western type • Prevented with vaccination and controlling mosquitoes • No effective treatment

22. Equine Abortion • May be caused by bacteria, viruses or fungi • Other causes: hormone deficiencies, carrying twins, genetic defects or other misc. factors • May occur at various times during pregnancy depending on the cause • Virus abortions may be prevented by vaccination • Bacterial abortions are best prevented by sanitation at breeding time • Isolate horses that have aborted • Bedding and aborted fetus should be burned or buried • Area should be disinfected • No vaccination for fungi-caused abortions

23. Equine Infectious Anemia (Swamp Fever) • Caused by a virus • Carried from horse to horse by bloodsucking insects • Symptoms • Fever, depression, weight loss, weakness, swelling in the legs • Death often occurs within 2-4 weeks • Chronic forms cause recurring attacks; horses with the chronic form also become carriers • Pregnant mares may abort • Infected horses are destroyed and the carcasses carefully disposed of • Only buy horses that have been tested and found free of disease • Control all bloodsucking insects • Practice sanitation and sterilize all instruments used on horses after each horse • No vaccine or treatment

24. Equine Influenza (Flu) • Caused by viruses • Spreads quickly where large numbers of horses are brought together • Symptoms • High temp, lack of appetite, watery nasal discharge • Young horses are more likely infected • Isolate newly arrived horses and those that have the disease • Treat with antibiotics and allow the animal to rest

25. Fescue Toxicity (Fescue Foot) • Caused by, a fungus that grows inside tall fescue • Fungus produces toxins that inhibit prolactin, a hormone that is essential to the last months of gestation for udder development and colostrums formation • Can also cause lameness, sloughing off the end of the tail, poor weight gain, increase in temperature, pulse and respiration rate • No treatment • Remove animals from fescue pasture when symptoms occur

26. Founder (Laminitis) • Nutritional disorder • Common causes are overeating of concentrates, sudden change in feed, drinking to much water, standing in a stall for long periods of time • May occur in chronic and acute forms • Care in feeding and management help to prevent founder • Cold applications should be used to treat the acute form • Chronic cases are treated by trimming the hoof and shoeing the horse

27. Acute Founder • Swelling of the sensitive laminae on one or more feet, lameness, fever, sweating • Distortion of the hoof

28. Heaves (Broken Wind, Asthma) • Nutritional disorder that affects the respiratory system • Often occurs when moldy or dusty feed is fed • More common in horses over five years of age • Affected horses have difficulty breathing, the air is forced from the lungs by the abdominal muscles, dry cough, nasal discharge, weight loss • Best prevention is to use care in feed selection and never feed moldy or dusty hay • Changing to a pelleted ration may help if the disease hasn’t progressed to far. • Putting the horse on pasture may also help • No treatment for advanced cases

29. Heaves Heave Lines

30. Lameness • Different causes • Many of the unsoundness's of the feet and legs result in lameness

31. Navel Ill (Joint Ill, Actinobacillosis) • Caused by bacteria • Affects newborn foals • Foal refuses to nurse and shows swelling and stiffness in the joints • May have a fever • Foal does not move around • In older foals—loss of appetite, weight loss • Sanitation and dipping the navel in tincture of iodine at birth help prevent navel ill • Antibiotics are used to treat.

32. Navel Ill

33. Periodic Ophalmia (Moon Blindness) • Exact cause is not known • Believed to be caused by infection • Affects older horses more • One or both eyes become swollen and the horse keeps its eyes closed • Watery discharge from the eye • Cornea may become cloudy • Attack usually clears up in a week to 10 days • The eye may not show much effect or the horse may be blind • Attacks recur at periodic intervals

34. Moon Blindness

35. Pneumonia • Caused by bacteria and viruses • Stress increases the chances of infection • Inhaling dust, smoke or liquids can also increase chances • Sometimes occurs as a complication of other diseases • Symptoms • Fever, rapid breathing, loss of appetite, chest pains • Sanitation and prevention of stress will help prevent the disease

36. Rabies (Hydrophobia) • Caused by a virus • Enters the body when the horse is bitten by an infected dog or wild animal • Affected horses become violent, drool and eventually become paralyzed and die • Prevented by vaccinating dogs and controlling wild animals known to carry the disease

37. Tetanus (Lockjaw) • Caused by bacteria • Bacteria usually enter through a puncture wound • Animal becomes nervous and stiff followed by muscle spasms and paralysis • Death occurs in untreated cases • Prevented by vaccination • Unvaccinated horses are given tetanus antitoxin serum if injured

38. Vesicular Stomatitis • Caused by a virus • Horse drools saliva and blisters form in the mouth • Provide water and soft feed • No vaccination for the disease

39. External Parasites

40. Common External Parasites • Flies • Lice • Mites • Ringworm • Ticks • Treatment and prevention was discussed in Unit 17

41. Horse Botflies • Produce larvae that are parasitic to horses • Leg eggs in the horses hair • Damage can be both direct and indirect • Controlled by killing the larvae in the stomach

42. Internal Parasites

43. Internal Parasites • Widespread, all horse are affected by them • Heavy infestations lead to poor physical condition • Extreme cases may cause death

44. Symptoms • Weight loss • Listlessness and poor performance • Dry, rough hair • Poor appetite • Bowel problems and colic • Periodic lameness • Breathing problems and coughing • Anemia • Foals that do not grow well and develop pot bellies

45. Diagnosis • Only sure way is veterinary examination of both the horse and the feces • Worm eggs revel what type of parasite is affecting the horse

46. Treatment • Drugs • No one drug is effective against all the different parasites • Worm medications can be purchased in several forms and administered in different ways

47. Life Cycles • Strongyles, ascarids, pinworms • Eggs are passed out in the feces • Eggs develop to infective stage on vegetation or in litter; or eggs hatch and larvae attach to vegetation • Horse picks up infective eggs or larvae fro vegetation or contaminated litter or water • Eggs hatch, larvae migrate through tissues of horses body • Larvae develop into mature worms and lay eggs

49. Large Strongyles • Migrate to the arteries, liver, gut wall • Adults are bloodsuckers • Blood clots may form in the arteries, resulting in blockage and death • Considered the most serious

50. Small Strongyle • Larvae migrate to the intestine • Cause digestive problems • Not as serious as the large strongyle